MARCOS ROJO has issued a grovelling apology to Sporting Lisbon in a bid to smooth through his move to Manchester United.

Rojo has apologised to Sporting Lisbon in a bid to smooth through his move to United [GETTY]

Argentina left-back Rojo went on "strike" last week and refused to train after Sporting rejected United's £16million offer.

But he has now apologised for his behaviour as the two clubs and Doyen Sports, the third-party investment group who own his economic rights, try and hammer out a deal.

He said: "I was hot-headed and I'm sorry. I'll be back with the rest of the squad on Monday.

"Sporting signed me when I was not at my best and gave me the opportunity to play for a big club in Europe. I would like to thank the trust they had in me and I will resume training."

United are cautiously confident they can overcome the row between Doyen and Sporting over Rojo. And they are ready to offer the Portugeuse club either Nani or Anderson in a player plus cash exchange.

Sporting are understood to be holding out for a £24m deal that will activate a release clause and enable them to bank more money as much of the cash from any possible deal would go to Doyen who own 75 per cent of Rojo.

Doyen are due three quarters of the fee that Sporting rejected when United made the £16m bid.

I was hot-headed and I'm sorry. I'll be back with the rest of the squad on Monday

Marcos Rojo

While they accept Sporting have the right to reject offers, the company say the club must pay up under the terms of contracts agreed.

It has put the two parties at war - with United caught in the middle - and there is also the added complication that Rojo's former club, Spartak Moscow, will be due 20 per cent of any fee Sporting receive.

Van Gaal has identified the versatile 24-year-old Rojo as the perfect player to bolster a depleted defensive unit that lost the wealth of experience of captain Nemanja Vidic, Rio Ferdinand and Patrice Evra in the summer.

He can play left back, centre back and even in midfield.

But Van Gaal has been warned there is 'no quick fix' to United's problems.

Rene Meulensteen, United's former first-team coach, warned his fellow Dutchman Van Gaal that he must sign at least four top players to turn the club into Premier League title contenders.

The need for reinforcements was underlined when Swansea shattered Van Gaal's hopes of a winning start to his reign at Old Trafford on Saturday.

"This is not going to be a quick fix," said Meulensteen. "They have still got two weeks to go in this transfer window.

"They definitely need to maximise the opportunities in this window and probably in January as well.

"We need to strengthen at the back, we need to strengthen in midfield and that is foremost the two areas they need to look at. In my opinion, they need to bring in at least four top players to really crank up the level."

Meulensteen also claimed that former boss David Moyes made it impossible for him to stay at Old Trafford following Ferguson's retirement last summer because he told him he wanted to do all the coaching himself.

He said: "He [Moyes] says he asked me to stay but he didn't say what he then said after that. He said, 'well, I would like you to stay, I know how important you have been for the club and what you have done for the club, but I am going to do it all myself'. So it was then, 'OK, what is the reason for me to stay'?

"That has not been documented and that is why you get all these wrong, mixed messages about why I didn't stay.

"So after being there for five years with Sir Alex Ferguson, being an integral part in training, planning, executing and the whole lot, suddenly you have been sidelined."